Cal. Penal Code § 1170.127

(a) A person who is committed to a state hospital after being found not guilty by reason of insanity pursuant to Section 1026 may petition the court to have his or her maximum term of commitment, as established by Section 1026.5, reduced to the length it would have been had Section 1170.126 been in effect at the time of the original determination. Both of the following conditions are required for the maximum term of commitment to be reduced:
1. (1) The person would have met all of the criteria for a reduction in sentence pursuant to Section 1170.126 had he or she been found guilty.
2. (2) The person files the petition for a reduction of the maximum term of commitment before January 1, 2021, or on a later date upon a showing of good cause.
(b) If a petitioner’s maximum term of confinement is ordered reduced under this section, the new term of confinement must provide opportunity to meet requirements provided in subdivision (b) of Section 1026.5. If a petitioner’s new maximum term of confinement ordered under this section does not provide sufficient time to meet requirements provided in subdivision (b) of Section 1026.5, the new maximum term of confinement may be extended, not more than 240 days from the date the petition is granted, in order to meet requirements provided in subdivision (b) of Section 1026.5.